Blackberries (Rubus subgenus Rubus Watson) are a well-known, aggregate fruit that are becoming increasingly popular throughout the world. Recent efforts at the University of Arkansas, using traditional breeding techniques and testing selections under mild climate conditions along the western coast of the USA, have led to the development of the world's first primocane-fruiting cultivars. Primocane-fruiting blackberries, in contrast to floricane-fruiting types, provide growers with the ability to produce fruit on first year canes (i.e., primocanes), as well as second-year canes (i.e., floricanes). In addition, primocane-fruiting blackberries produce fruit in late summer to autumn, whereas floricane-fruiting types generally fruit in early to mid-summer. The ability to extend the harvest season offers fresh market growers a significant economic advantage.
One example of an existing primocane-fruiting blackberry variety is ‘APF-45’ (marketed under the trade name ‘PRIME ARK® 45’), U.S. Plant Pat. No. 22,449. Another example of an existing, patent-pending primocane-fruiting blackberry variety is ‘Camila’, U.S. Plant Pat. No. 26,368. A further example of an existing primocane-fruiting blackberry variety is ‘Reuben’, U.S. Plant Pat. No. 23,497.
Compared to ‘APF-45’, the present cultivar, ‘APF-122’, is different because the fruit size is smaller (5.8 g vs. 8.8 g, on average) and significantly earlier in fruiting season (average ripe fruit date for primocanes on ‘APF-122’ is 5-6 months after planting vs. 8-9 months after planting ‘APF-45’).
Compared to ‘Camila’, the fruit shape of ‘Camila’ is elongated, while the fruit shape of ‘APF-122’ is round. Fruits of ‘Camila’ have only moderate firmness, while ‘APF-122’ is very firm.
Compared to ‘Reuben’, the fruits of ‘Reuben’ are much larger than ‘APF-122’, averaging 14.5 g versus 5.8 g, respectively. Also, ‘Reuben’ is a late-fruiting variety, while ‘APF-122’ is considered early for a primocane-fruiting type. The fruits of ‘Reuben’ are oblong and blocky, while fruits of ‘APF-122’ are round.
Distinctive characteristics of ‘APF-122’ include its precocity, high soluble solids (even at the red-black stage) and very little postharvest reddening (<10%). ‘APF-122’ is also unique in that it over-crops so heavily on its compact primocanes that a floricane crop would generally not be economically viable. Normally in commercial practice, primocane-fruiting
blackberries are pinch pruned (i.e., the tips are pinched out at the appropriate stage of growth) in order to force more fruiting laterals. However, in the case of ‘APF-122’, given its high yield potential and precocity, it may prove that in commercial practice that the need for such pinching may be reduced or even eliminated.